Acoustic coupler



FIG. 1 is a front view of an acoustic coupler; showing my new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a side elevational view as seen from the left of FIG. 1;

FIG. 6 is a side elevational view as seen from the right of FIG. 1; and

FIG. 7 is a perspective view thereof. 

The ornamental design for an acoustic coupler, as shown and described. 